Rate matching around synchronization signal blocks in unlicensed spectrum

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station may transmit, and a user equipment (UE) may receive, a bitmap that includes a bit sequence to indicate a synchronization signal block (SSB) transmission pattern. The UE may perform rate matching around one or more candidate SSB positions in an initial portion of a window in which SSB transmission is expected, based at least in part on the bitmap, a first parameter indicating a quantity of initial candidate SSB positions in the window subject to rate matching, and a second parameter indicating a quantity of initial bits in the bit sequence that define the SSB transmission pattern. Numerous other aspects are provided.

What is claimed is: 
     
       1. A method of wireless communication performed by a user equipment (UE), comprising:
 receiving, from a base station, a bitmap that includes a bit sequence to indicate a synchronization signal block (SSB) transmission pattern; and 
 performing rate matching around one or more candidate SSB positions in an initial portion of a window in which SSB transmission is expected, based at least in part on the bitmap, a first parameter indicating a quantity of initial candidate SSB positions in the window that are subject to rate matching, and a second parameter indicating a quantity of initial bits in the bit sequence that define the SSB transmission pattern. 
 
     
     
       2. The method of  claim 1 , wherein one or more of the first parameter or the second parameter is equal to a quantity of beams used by the base station to transmit SSBs in the window. 
     
     
       3. The method of  claim 1 , wherein the first parameter is equal to one or more of a total quantity of candidate SSB positions in the window or a total quantity of candidate SSB positions in a maximum duration for the window. 
     
     
       4. The method of  claim 1 , wherein one or more of a value of the first parameter or a bit length of the bit sequence is based at least in part on a subcarrier spacing used in a cell associated with the base station. 
     
     
       5. The method of  claim 1 , wherein the SSB transmission pattern defined by the quantity of initial bits in the bit sequence repeats over the quantity of initial candidate SSB positions in the window that are subject to rate matching. 
     
     
       6. The method of  claim 1 , wherein the bit sequence has a maximum bit length greater than or equal to a total quantity of candidate SSB positions in the window. 
     
     
       7. The method of  claim 1 , further comprising:
 receiving, from the base station, scheduling information including a resource allocation that avoids collisions with one or more SSB transmissions that occur after the quantity of initial candidate SSB positions indicated by the first parameter. 
 
     
     
       8. The method of  claim 1 , further comprising:
 receiving, from the base station, downlink control information including one or more rate matching bits to indicate a rate matching pattern for one or more SSB transmissions scheduled to occur after the quantity of initial candidate SSB positions indicated by the first parameter; and 
 performing rate matching around the one or more SSB transmissions scheduled to occur after the quantity of initial candidate SSB positions, based at least in part on the rate matching pattern indicated by the one or more rate matching bits. 
 
     
     
       9. The method of  claim 1 , further comprising:
 receiving, from the base station, one or more bits in downlink control information to indicate one or more SSB positions in which to perform rate matching after the quantity of initial candidate SSB positions indicated by the first parameter; and 
 performing rate matching around the one or more SSB positions indicated by the one or more bits in the downlink control information. 
 
     
     
       10. The method of  claim 1 , further comprising:
 receiving, from the base station, signaling indicating the window in which the SSB transmission is expected. 
 
     
     
       11. A method of wireless communication performed by a base station, comprising:
 transmitting, to a user equipment (UE), a bitmap that includes a bit sequence to indicate a synchronization signal block (SSB) transmission pattern; and 
 scheduling transmission of one or more SSBs in one or more candidate SSB positions in an initial portion of a window in which SSB transmission is expected by the UE based at least in part on the SSB transmission pattern, wherein the UE performs rate matching around the one or more candidate SSB positions in the initial portion of the window, based at least in part on the bitmap, a first parameter indicating a quantity of initial candidate SSB positions in the window that are subject to rate matching, and a second parameter indicating a quantity of initial bits in the bit sequence that define the SSB transmission pattern. 
 
     
     
       12. The method of  claim 11 , wherein one or more of the first parameter or the second parameter is equal to a quantity of beams used by the base station to transmit the one or more SSBs. 
     
     
       13. The method of  claim 11 , wherein the first parameter is equal to one or more of a total quantity of candidate SSB positions in the window or a total quantity of candidate SSB positions in a maximum duration for the window. 
     
     
       14. The method of  claim 11 , wherein one or more of a value of the first parameter or a bit length of the bit sequence is based at least in part on a subcarrier spacing used in a cell associated with the base station. 
     
     
       15. The method of  claim 11 , wherein the SSB transmission pattern defined by the quantity of initial bits in the bit sequence repeats over the quantity of initial candidate SSB positions in the window that are subject to rate matching. 
     
     
       16. The method of  claim 11 , wherein the bit sequence has a maximum bit length greater than or equal to a total quantity of candidate SSB positions in the window. 
     
     
       17. The method of  claim 11 , further comprising:
 transmitting, to the UE, scheduling information including a resource allocation that avoids collisions with one or more SSB transmissions that occur after the quantity of initial candidate SSB positions indicated by the first parameter. 
 
     
     
       18. The method of  claim 11 , further comprising:
 transmitting, to the UE, downlink control information including one or more rate matching bits to indicate a rate matching pattern for one or more SSB transmissions scheduled to occur after the quantity of initial candidate SSB positions indicated by the first parameter; and 
 performing the one or more SSB transmissions according to the rate matching pattern indicated by the one or more rate matching bits, wherein the UE performs rate matching around the one or more SSB transmissions based at least in part on the rate matching pattern indicated by the one or more rate matching bits. 
 
     
     
       19. The method of  claim 11 , further comprising:
 transmitting, to the UE, one or more bits in downlink control information to indicate one or more SSB positions in which to perform rate matching after the quantity of initial candidate SSB positions indicated by the first parameter; and 
 performing one or more SSB transmissions in the one or more SSB positions indicated by the one or more bits in the downlink control information, wherein the UE performs rate matching around the one or more SSB positions based at least in part on the one or more bits in the downlink control information. 
 
     
     
       20. The method of  claim 11 , further comprising:
 transmitting, to the UE, signaling indicating the window in which to expect the SSB transmission. 
 
     
     
       21. A user equipment (UE) for wireless communication, comprising:
 a memory; and 
 one or more processors operatively coupled to the memory, the memory and the one or more processors configured to:
 receive, from a base station, a bitmap that includes a bit sequence to indicate a synchronization signal block (SSB) transmission pattern; and 
 perform rate matching around one or more candidate SSB positions in an initial portion of a window in which SSB transmission is expected, based at least in part on the bitmap, a first parameter indicating a quantity of initial candidate SSB positions in the window that are subject to rate matching, and a second parameter indicating a quantity of initial bits in the bit sequence that define the SSB transmission pattern. 
 
 
     
     
       22. The UE of  claim 21 , wherein one or more of the first parameter or the second parameter is equal to a quantity of beams used by the base station to transmit SSBs in the window. 
     
     
       23. The UE of  claim 21 , wherein the first parameter is equal to one or more of a total quantity of candidate SSB positions in the window or a total quantity of candidate SSB positions in a maximum duration for the window. 
     
     
       24. The UE of  claim 21 , wherein the memory and the one or more processors are further configured to:
 receive, from the base station, downlink control information including one or more rate matching bits to indicate a rate matching pattern for one or more SSB transmissions scheduled to occur after the quantity of initial candidate SSB positions indicated by the first parameter; and 
 perform rate matching around the one or more SSB transmissions scheduled to occur after the quantity of initial candidate SSB positions, based at least in part on the rate matching pattern indicated by the one or more rate matching bits. 
 
     
     
       25. The UE of  claim 21 , wherein the memory and the one or more processors are further configured to:
 receive, from the base station, one or more bits in downlink control information to indicate one or more SSB positions in which to perform rate matching after the quantity of initial candidate SSB positions indicated by the first parameter; and 
 perform rate matching around the one or more SSB positions indicated by the one or more bits in the downlink control information. 
 
     
     
       26. A base station for wireless communication, comprising:
 a memory; and 
 one or more processors operatively coupled to the memory, the memory and the one or more processors configured to:
 transmit, to a user equipment (UE), a bitmap that includes a bit sequence to indicate a synchronization signal block (SSB) transmission pattern; and 
 schedule transmission of one or more SSBs in one or more candidate SSB positions in an initial portion of a window in which SSB transmission is expected by the UE based at least in part on the SSB transmission pattern, wherein the UE performs rate matching around the one or more candidate SSB positions in the initial portion of the window, based at least in part on the bitmap, a first parameter indicating a quantity of initial candidate SSB positions in the window that are subject to rate matching, and a second parameter indicating a quantity of initial bits in the bit sequence that define the SSB transmission pattern. 
 
 
     
     
       27. The base station of  claim 26 , wherein one or more of the first parameter or the second parameter is equal to a quantity of beams used by the base station to transmit the one or more SSBs. 
     
     
       28. The base station of  claim 26 , wherein the first parameter is equal to one or more of a total quantity of candidate SSB positions in the window or a total quantity of candidate SSB positions in a maximum duration for the window. 
     
     
       29. The base station of  claim 26 , wherein the memory and the one or more processors are further configured to:
 transmit, to the UE, downlink control information including one or more rate matching bits to indicate a rate matching pattern for one or more SSB transmissions scheduled to occur after the quantity of initial candidate SSB positions indicated by the first parameter; and 
 perform the one or more SSB transmissions according to the rate matching pattern indicated by the one or more rate matching bits, wherein the UE is to perform rate matching around the one or more SSB transmissions based at least in part on the rate matching pattern indicated by the one or more rate matching bits. 
 
     
     
       30. The base station of  claim 26 , wherein the memory and the one or more processors are further configured to:
 transmit, to the UE, one or more bits in downlink control information to indicate one or more SSB positions in which to perform rate matching after the quantity of initial candidate SSB positions indicated by the first parameter; and 
 perform one or more SSB transmissions in the one or more SSB positions indicated by the one or more bits in the downlink control information, wherein the UE is to perform rate matching around the one or more SSB positions based at least in part on the one or more bits in the downlink control information.